Humans are omnivorous animals that can consume both plant and animal products. We changed from gatherers to hunter gatherers. After the experience of the Ice Age it is probable that humans wanted to create some feeling of security by controlling what plants were growing and which animals were available. This led to agriculture, which has continually improved and altered the way in which food is obtained.

In societies where the availability of food has risen above subsistence levels and beyond staple foods, food is also sold pre-prepared for immediate consumption in restaurants and other similar retail premises. In industrial societies, meals often contain a higher proportion of food of animal origin.

At the start of the 21st century, a two-tier structure has arisen, with a few international food processing giants controlling a wide range of well known food brands; with a populous number of small local or national food processing companies.

Food is now traded on a global basis. The variety and availability of food is no longer restricted by the diversity of locally grown food or the limitations of the local growing season. Between 1961 and 1999 there has been a 400% increase in worldwide food exports. Some countries are now economically dependant on food exports, which in some cases account for over 80% of all exports.

The sale of surplus food traditionally took place once a week when farmers took their wares on market day, into the local village market place. Here food was sold to grocers for sale in their local shops for purchase by local people.

With the onset of industrialisation, and the development of the food processing industry, a wider range of food could be sold and distributed in distant locations. Typically early grocery shops would be counter-based shops, in which purchasers told the shop-keeper what they wanted, so that the shop-keeper could get it for them.

In the 20th century supermarkets were born. Supermarkets brought with them a self-service approach to shopping using shopping carts (or Trollies in British English) and were able to offer quality food at lower cost, through economies of scale and reduced staffing costs. This was sometimes known as 'pile it high' In the latter part of the 20th century, this has been further revolutionised by the development of vast warehouse sized out-of-town supermarkets, selling an extraordinarily wide range of food from around the world.

Alike with food processors, food retailing is a two-tier market in which a small number of very large companies control a large proportion of supermarkets. The supermarket giants wield great purchasing power over farmers and processors, and strong influence over consumers. Nevertheless, in 2000 only 19% of all US consumer expenditure spent on food went to farmers.

Recent technological innovations such as point of sale technology - barcodes. This allows ordering of goods and food to be driven by actual sales.

Food deprivation leads to malnutrition and ultimately starvation. This is often connected with famine, which involves the absence of food in entire communities. This can have a devastating and widespread effect on human health and mortality. In 2003 it was estimated that each year, 40 million people die of hunger worldwide. Rationing is sometimes used to fairly the equal distribution of food in times of shortage, most notably during times of war.

Understanding of the causes of food-borne-illnesses and more systematic techniques for their elimination has led to the development of commercial systems such as HACCP which can, if properly implemented, identify and can eliminate all possible risks.

Certain foods contain allergens which can safely be consumed by the majority by people. However, these can trigger severe illness in small proportion of susceptible people. Rarely this can trigger anaphylaxis which can be fatal.

Concerns about foodborne illness have long influenced diet. Traditionally humans have leant to avoid foods that induce acute illness. Some believe that this is the underlying rationale behind some traditional religious dietary requirements. Additionally, many people choose to forgo food from animal sources to varying degrees; see vegetarianism, veganism, fructarianism , living foods diet, and raw foodism.